Illustrations from a 1925 edition of Aesop's Fables, from 50 Watts fave Takeo Takei
Bio from the Kodomo No Kuni site:
Takei was born in Suwa, Nagano prefecture in 1894. After studying at the Hongo Yoga Kenkyujo (Hongo Research Institute for Western Art) he entered the Western-style art department of Tokyo Art School in 1919. He was an ardent admirer of illustrator Takehisa Yumeji and poet Kitahara Hakushu. After graduation from art school, he married in 1921 and to support his new family he began to produce illustrations for children for Kodomo no tomo [Child's Friend], a children's magazine published by Fujin no Tomo Sha. In 1922 he became one of the leading illustrators for Kodomo no kuni [Children's Land] from its inaugural issue. In 1923 he published Otogi no tamago [The Fairy's Egg], and in 1925 his first individual exhibition was held in Ginza in the heart of Tokyo. His Ramu-ramu O [King Ramu-ramu] came out in 1926. The following year, with Shimizu Yoshio, Okamoto Kiichi, Kawakami Shiro, and other illustrators contributing to the Kodomo no kuni, Takei formed the Nihon Doga Kyokai (Japan Association of Illustration for Children), as part of the effort to achieve artistic quality in illustrations for children. Following Okamoto's death, Takei succeeded him as critic and selector of illustrations submitted to Kodomo no kuni in 1931. In 1955, he became editorial adviser for the magazine Kinda bukku [Kinder Book].
I again found these images in the database of the National Diet Library.
Some of Takei's books have been reprinted and are available from amazon.co.jp.